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wrong density of material air in a tube
Posted 4 nov. 2014, 08:24 UTC−5 Fluid & Heat, Heat Transfer & Phase Change, Materials Version 4.2a 0 Replies
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The heater should result in a density change in in the air flow.
Because of rho = presure / (Rs(gas constant) * temperature)
according to literature for the density:
1.2049194 kg/m^3 at 20 degC to
0.7451498 kg/m^3 at 200 degC
But if I plot the density over the tube length
2.40 kg/m^3 at the inflow start point (should correspond to 20 degC)
1.51 kg/m^3 at the outflow of the tube (should correspond to 200 degC)
The presure chances over the tube length about round 0,4 mbar in the simulation. What is correct according to the Hagen–Poiseuille equation.
I seams to be the the values for the density in the simlation is nearly the double of the literature value.
what I'm doing wrong?
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Hello Peter Miller
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